Background: Health related quality of life (HRQOL) is a pivotal concern for early stage prostate cancer survivors and their spouses. Recent developments, including the emergence of brachytherapy (BT), the development of 3-D conformal radiotherapy (3D-ERT), the increased use of adjuvant hormonal therapy, and the observation that radical prostatectomy (RP) outcomes may differ between practitioners, fuel a need to re-evaluate HRQOL outcomes in this context. HRQOL following BT, 3D-ERT, and RP have not been characterized with an instrument validated to detect effects of each of these interventions. Moreover, patient or provider determinants of patient HRQOL, patient satisfaction, and spouse satisfaction remain uncharacterized. Because prostate cancer survivors and experts determined that existing HRQOL instruments lacked key items for concurrently evaluating HRQOL effects of BT, ERT, and RP, we developed and validated the Expanded Prostate Cancer Index Composite (EPIC) instrument using a cohort that equally represented each of these 3 interventions. Factor analysis revealed 2 new HRQOL domains (urinary-irritative and hormonal) complementing the 3 function domains of UCLA-PCI (urinary-incontinence, bowel, sexual). The 5 HRQOL domains measured by EPIC showed satisfactory internal consistency, reliability, and external validity. Cross-sectional HRQOL comparison among 1014 BT, 3D-ERT, or RP survivors and controls showed that each EPIC HRQOL domain was adversely affected by at least one of the therapies. EPIC HRQOL domain scores associated significantly with patient satisfaction and were sensitive to baseline factors such as age, cancer severity, and prostate size. We hypothesize that patient and provider characteristics affect HRQOL changes after brachytherapy, external radiation, or prostatectomy, and that these interventions have different HRQOL effects, which impact long-term patient and spouse satisfaction. The proposed observational study has the following Specific Aims: 1) To assess baseline determinants, including provider characteristics, of long-term HRQOL after BT, 3D-ERT, or RP; 2) To characterize baseline determinants of patient and spouse satisfaction with intervention process and outcome; and 3) To evaluate effects of therapy choice on HRQOL outcome and satisfaction. Experimental Design: A prospective, observational, multi-institutional study will be performed at 5 institutions with pre-existing, multi-disciplinary expertise in BT, 3D-ERT, and RP. Patients with early stage prostate cancer electing to undergo BT, 3D-ERT, or RP as primary therapy will be eligible. Baseline demographics, cancer severity measures, and provider characteristics will be recorded, while HRQOL will be measured using the EPIC survey instrument administered at baseline (pre-therapy); then at 2 months, 6 months, and yearly after therapy for 3 years. The multidimensional SSS-10 instrument, administered to survivors and their spouses or life partners, will measure satisfaction with process and outcome. The principal endpoints will be changes in EPIC domain summary scores from baseline to two years after therapy, and survivor satisfaction as well as spouse satisfaction. For each procedure, HRQOL changes over time and yearly satisfaction scores will be modeled by a mixed effects model; baseline risk factors that affect change will be identified. The effects of each therapy on change in HRQOL will be compared after controlling for risk factors identified in the previous step. The findings from this prospective, observational study will provide benchmarks to guide outcomes expectations and to facilitate evidence-based decisions regarding therapy.